1. Technical Field
The invention relates to a lens, and more particularly to an imaging lens.
2. Related Art
In recent years, the market for the portable electronic products such as slim digital camera, mobile phone or tablet personal computer is booming with the benefit of advancing technology. For such products, photography or shooting is already one of the indispensable functions. Under this circumstance, the demand for miniaturized imaging lens is increasingly higher.
Regarding the entry-type of low pixel camera module, a suitable imaging lens may be composed of 2 lenses or less, in order to satisfy the requirement for resolving images. The required quantity of lenses for an imaging lens may also increase with the increase of in the number of pixels, such as a camera module with more than two million pixels requires four lenses to compose of an imaging lens. Besides, in order to satisfy a camera module with more than eight millions pixels, five lenses are generally adopted to compose of an image lens. In other words, when the imaging lens of a camera module uses more lenses, the entire optical length of the imaging lens may become longer, but this may cause the following issue, i.e., unable to satisfy the requirement of slim camera module.
At the current stage, in the increasing trend toward slim and high performance of the electronic products, designing an imaging lens having a shorter optical length and a fine aperture with the limited number of lenses (such as a configuration with five lenses) has become an important issue in the related fields.